The technology of catalytic cracking employing crystalline zeolite conversion catalyst has been the subject of continuous investigation since the development of the cystalline zeolite cracking catalyst. As new zeolites are developed and their properties studied, changes in processing technology are recognized and pursued with a view to reducing the overall economics of the refining operation. The present invention is related to an improvement of this kind and is particularly directed to reducing the size of the refinery light ends recovery operation by processing light end products of fluid cracking over relatively specific small pore zeolite catalyst which particularly promote the formation of olefin oligomers and polymers as well as cyclization of olefins to form aromatics.